Mixing blade for concrete mixer

Abstract

An improved and more rapid mixing of concrete is achieved in a rotary concrete mixing drum according to the present invention by the simple expedient of providing passages which open through the body of the mixing blade which permit concrete flow therethrough. The flow of concrete through the passages creates added turbulence in the body of concrete during the rotation of the mixing drum in the mixing direction. The concrete is prevented from passing directly through the same mixing passages when the mixing drum is rotated in the discharged direction by mounting deflector blades on the discharge face which extend over the mixing passages and deflect the concrete aggregate away from the mixing passages during rotation of the mixing blades in the discharge direction.

What I claim as my invention is: 
     
       1. In a rotary concrete mixing drum mounted for rotation about a rotary axis, said mixing drum having a mixing chamber formed therein, said mixing chamber having a head end and a discharge end arranged opposite one another, a mixing blade disposed within said mixing chamber, said mixing blade having a mixing face directed toward said head end to establish a fluid flow in a direction toward said head end of said chamber in response to rotation of said blades in a mixing direction about said rotary axis and a discharge face directed toward the discharge end of said mixing drum to establish a fluid flow in a direction toward said discharge end of said chamber in response to rotation in said discharge direction, the improvement of; (a) a plurality of mixing passages opening through said mixing blade between said mixing face and said discharge face whereby wet concrete will pass through said mixing passages from said mixing face to said discharge face in response to rotation of said drum in said mixing direction and thereby establish turbulence in the mixing chamber,   (b) a deflector blade mounted on said discharge face of said mixing blade in advance of each mixing passage in the discharge direction, said deflector blade being adapted to deflect the flow of wet concrete away from its associated mixing passage to permit discharge of wet concrete from said discharge end in response to rotation in said discharge direction.   
     
     
       2. A rotary concrete mixing drum as claimed in claim 1 wherein each deflector blade comprises a rigid blade which is upwardly and rearwardly inclined above its associated mixing passage. 
     
     
       3. A rotary concrete mixing drum as claimed in claim 1 wherein said mixing passages and their associated deflector blades are provided on each mixing blade of said rotary mixer. 
     
     
       4. A rotary concrete mixing drum as claimed in claim 1 wherein said mixing passages and their associted deflector blades are located at uniformly spaced intervals along the length of said mixing blade. 
     
     
       5. A rotary concrete mixing drum as claimed in claim 1 wherein said mixing passages and their associated deflector blades are located at spaced intervals over at least two thirds of the length of said mixing blade measured from said head end of said mixing chamber.